SMbus ControllersThe CPU provides 3 SMbus controllers, and these are used to connect up various SMbus andI2C devices. The number of SMbusses is expanded to 7 via a 1:4 multiplexer on SMbus 1.

SMbus 0 is connected to the 4 DIMM sockets to support Serial Presence Detect (SPD). It is also connected to a standard 24LC128 EEPROM, and a temperature sensor (Texas Instruments TMP423). This sensor is connected to the CPU on-die temperature diodes for the 2 cores and SOC (main logic).